Kepler-10
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Draco |
| Right ascension | 19h 02m 43s |
| Declination | +50° 14′ 29″ |
| Apparent magnitude (V) | 10.960 |
| Astrometry | |
| Distance | 564 ly (173[1] pc) |
| Characteristics | |
| Spectral type | G[1] |
| Details | |
| Mass | 0.895 ± 0.06[1] M☉ |
| Radius | 1.056±0.021[1] R☉ |
| Temperature | 5627 ± 44[1] K |
| Age | 11.9 ± 4.5[1] Gyr |
| Other designations | |
Kepler-10, formerly known as KOI-72, is a sunlike star in constellation Draco that lies 173 parsecs (564 light years) away from the Earth. Kepler-10 was targeted by NASA's Kepler spacecraft, as it was seen the first star identified by the Kepler mission as a possible host to a small, transiting exoplanet.[4] The star is slightly less massive, slightly larger, and slightly cooler than the Sun; at an estimated 11.9 billion years in age, Kepler-10 is almost 2.6 times the age of the Sun. Kepler-10 is host to a planetary system made up of at least two planets. Kepler-10b, the first undeniably rocky planet,[4] was discovered in its orbit after eight months of observation and announced on January 10, 2011. The planet orbits its star closely, completing an orbit every 0.8 days,[5] and has a density similar to that of iron.[4] The second planet, Kepler-10c, was confirmed on May 23, 2011, based on follow-up observations by the Spitzer Space Telescope. The data shows it has an orbital period of 42.3 days.[6]
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Nomenclature and history [edit]
Kepler-10 was named because it was the tenth planetary system observed by the Kepler spacecraft, a NASA satellite designed to search for Earth-like planets that transit, or cross in front of, their host stars with respect to Earth. The transit slightly dims the host star; this periodic dimming effect is then noted by Kepler.[7] After eight months of observation ranging from May 2009 to January 2010, the Kepler team established Kepler-10b as the first rocky exoplanet discovered by the Kepler satellite. Kepler-10 was the first Kepler-targeted star suspected of having a small planet in orbit. Because of that, verifying Kepler's discovery was prioritized by telescopes at the W.M. Keck Observatory in Hawaii. The discovery was successfully verified.[4] Although there had been many potentially rocky exoplanets discovered in the past, Kepler-10b was the first definitively rocky planet to have been discovered.[8]
The discovery of Kepler-10b was announced to the public at a winter meeting of the American Astronomical Society on January 10, 2011 in Seattle.[8] On May 23, 2011, the existence of Kepler-10c was confirmed at the 218th AAS meeting in Boston.[9]
Characteristics [edit]
Kepler-10 is a G-type star, like the Sun. With a mass of 0.895 (± 0.06) Msun and a radius of 1.056 (± 0.021) Rsun, the star is approximately 10% smaller than and 5% wider than the Sun. The metallicity of Kepler-10, as measured in [Fe/H] (the amount of iron in the star), is -0.15 (± 0.04); this means that Kepler-10 is about 70% less metal-rich than the Sun. Metallicity tends to play a large role in the formation of planets, determining if they form, and what kind of planet they will form.[10] In addition, Kepler-10 is estimated to be 11.9 billion years old and to have an effective temperature of 5627 (± 44) K;[1] To compare, the Sun is younger and hotter, with an age of 4.6 billion years[11] and an effective temperature of 5778 K.[12]
Kepler-10 is located at a distance of 173 (± 27) parsecs from the Earth, which equates to approximately 564 light years. Also, Kepler-10's apparent magnitude, or brightness as seen from Earth, is 10.96; it therefore cannot be seen with the naked eye.[1]
Planetary system [edit]
Kepler-10b, the first definitively rocky exoplanet, was discovered in the orbit of Kepler-10. The planet has a mass that is 4.56 times that of Earth's and a radius that is 1.416 times that of Earth. The planet's estimated density is 8.8 g/cm³, or 880% that of water. This is similar to that of iron.[4] The planet orbits Kepler-10 at a distance of 0.01684 AU every 0.8375 days;[5] this can be compared to the orbit and orbital period of planet Mercury, which circles the Sun at a distance of 0.3871 AU every 87.97 days.[13] Because the planet orbits so closely to its star, its eccentricity is virtually zero. It, thus, has an extremely circular orbit.[5]
Kepler-10c[6] is an exoplanet that was also discovered by NASA's Kepler Mission[14] in the orbit of Kepler-10. Measurements of the body suggest that it has a mass of at most 0.063 MJ and a radius of 0.199 RJ (2 Earth radii). Kepler-10c would orbit Kepler-10 at a distance of 0.24 AU every 42.29 days.[1]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 4.6±1.2 M⊕ | 0.01684 | 0.837495 | 0 | — | 1.416 R⊕ |
| c | < 20 M⊕ | 0.2407 | 42.29485 | 0 | — | 2.227 R⊕ |
See also [edit]
References [edit]
- ^ a b c d e f g h i "Notes for star Kepler-10". Extrasolar Planets Encyclopaedia. 2011. Retrieved 13 March 2011.
- ^ a b c "Kepler-10 -- Star". SIMBAD. Retrieved 2011-02-01.
- ^ Batalha, N. M.; et al. (2011). "Kepler's First Rocky Planet: Kepler-10b". The Astrophysical Journal 729: 27. arXiv:1102.0605. Bibcode:2011ApJ...729...27B. doi:10.1088/0004-637X/729/1/27.
- ^ a b c d e Perrotto, Trent J.; Hoover, Rachel (10 January 2011). "NASA'S Kepler Mission Discovers Its First Rocky Planet". Ames Research Center. NASA. Retrieved 13 March 2011.
- ^ a b c d "Summary Table of Kepler Discoveries". NASA. 2011. Retrieved 13 March 2011.
- ^ a b Fressin, F.; et al. (2011). "Kepler-10c, A 2.2-Earth Radius Transiting Planet In A Multiple System". arXiv:1105.4647 [astro-ph.EP].
- ^ "Kepler: About the Mission". Kepler Mission. NASA. 2011. Retrieved 13 March 2011.
- ^ a b Richard A. Lovett (10 January 2011). "NASA Finds Smallest Earthlike Planet Outside Solar System". National Geographic Society. Retrieved 13 March 2011.
- ^ "Kepler Spacecraft Shows That Smaller Planets Abound". Scientific American. 2011. Retrieved 2011-05-26.
- ^ Henry Bortman (12 October 2004). "Extrasolar Planets: A Matter of Metallicity". Space Daily. Retrieved 13 March 2011.
- ^ Fraser Cain (16 September 2008). "How Old is the Sun?". Universe Today. Retrieved 13 March 2011.
- ^ Ed Grayzeck. "Sun Fact Sheet". Goddard Space Flight Center. NASA. Retrieved 13 March 2011.
- ^ David Williams (17 November 2010). "Mercury Fact Sheet". Goddard Space Flight Center. NASA. Retrieved 27 February 2011.
- ^ "NASA'S Kepler Mission Discovers Its First Rocky Planet". NASA. 2011-01-10. Retrieved 2011-01-10.
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